Google Analytics allows users to compare historical traffic trends over different time periods. When comparing a selected date range to the previous period, the days of the week may not match up exactly. This can yield inaccurate results when analyzing weekly patterns. To ensure an accurate comparison of the same days of the week, users need to manually enter custom date ranges where the days match perfectly between the periods.

1. Google Analytics
Selecting Historical Trends &
Date Ranges
By: Errett Cord
Email: ecord@ecord.us
Twitter: @errettcord

2. Historical Traffic Trends
Google Analytics users only concern themselves with
current traffic trends, but identifying patterns based
on previous traffic can yield valuable insights into
how traffic can change over time. One of the best
ways to view historical data is by using the Compare
to Previous Period tool in the date range dialog box.

3. Historical Traffic Trends
When you’ve selected the desired date range (and the
previous period to compare it to), you can apply the
filter to see how the traffic compares from one time
period to another – in this case, from March 2 to April
30, and March 12 to April 11 (the previous period).

4. Date Ranges
Applying this filter to a weekly view, you might think
that a Monday-Sunday week view would mirror the
previous period exactly – but it doesn’t. Instead,
Google Analytics defaults to the number of days in the
specified period, not to the corresponding days of the
previous week.

5. Date Ranges
The first date range is Monday, May 5 to Friday, May 9.
This covers the a five-day business week for this period.
When we select “Compare to Previous Period,” Google
Analytics pulls data from the five-day period immediately
preceding the first date range, not the previous five-day
work week. This means the data included in the graph is
actually comparing completely different days of the week,
which displays bogus results.

6. Date Ranges
Make sure we specify a custom date range (in which the
days of the week match perfectly), you will see that the
two graphs are virtually identical. Note that to accomplish
this, you’ll need to enter the desired date range manually
in the relevant fields, rather than clicking on a start day
and letting Analytics fill in the blanks.